Big ships vs. pleasure boats

Posted on 19 November 2008

Don’t let anyone kid you; size does matter. Big ships versus pleasure boats are nolo contendere. In other words, you cannot win. Regardless of the Rules of the Road, COLREGS notwithstanding, the primary rule to remember is mass has the right of way.

I’m amazed at how cavalier some recreational boaters can be regarding ships, tugs, barges and the like. It’s true that a twin-screw or outboard boat is far more maneuverable and can accelerate faster than a ship to get out of harm’s way. But think about your luck running out — your engines stop or your steering fails, for instance. When problems occur, they do so at the worst possible time. Maybe you consider yourself lucky. The problem with luck, however, is that you can’t count on it.

1. Have you ever experienced the phenomenon of coming up on a marker or harbor and it seems to take forever and then suddenly it rushes up on you? The same thing happens with ships. They seem to be a long way off and moving very slowly and then there they be — on top of you. I’ve experienced it. One night, entering the Chesapeake from the Chesapeake Tower, I chose a route south of the outbound traffic lane. I started worrying about water depth, my delivery being a deep-draft sailboat. On this clear night, at some distance off, I saw the green sidelight and steaming light of a down-bound ship. It looked to be moving slowly, and I decided to cross the lane to get to deep water. Like a darn fool, I did not check the range on radar (unfortunately mounted below deck). We were committed to the crossing when I looked up and saw her red and green sidelights, close up and personal. Her bow was obscuring the sidelights as we squeaked past her and the pilot boat I hadn’t seen along her port side. I really don’t know what that second vessel was; I only saw her red and green lights closing on us. I heard her sound the danger signal while I prayed we’d be passed without being run down. We made it, though not by much. The larger of the two vessels didn’t sound a danger signal; we were too close for them to see our mast. If my delivery had tricolor lights mounted atop the mast, we might have been seen sooner. Bridge watches look ahead for other ships, they don’t look down.

2. The previous anecdote shows that the larger the ship is, the greater the blind area forward of its bow. A large ship can’t see anything closer than around a quarter-mile ahead, and even lighters and small cargo ships can’t see you up close. Remember, if you can’t see the bridge, the bridge can’t see you.

3. In addition to not seeing close objects from the bridge, ships can’t stop quickly. Most large ships have only one engine and no transmission. To operate astern propulsion, her engine must stop completely before reversing. Compressed air then forces the engine to start in the opposite direction. At sea speed, water pressure on the screw can prevent it from turning in reverse. The counter flow of water over the rudder then causes a loss of control, and the ship’s motion becomes unpredictable. I know of no ship’s master who would risk loss of control, especially in confined or crowded waters.

4. With the engine stopped, inertia will continue a ship’s forward motion. Depending on the size and speed of the vessel, it can take more than a half-mile to stop.

5. When a ship turns, the change in rudder angle affects the aspect of the vessel; it continues to advance along its original track before its direction changes. Again, depending on size and speed, it could take a half-mile to execute a change in direction.

6. Tugboats have a tough time maneuvering or stopping. Tows don’t have engines, but they have inertia, which causes them to continue their original track regardless of the tug’s actions. Never attempt to cross between a tug and its tow. At night, be sure to look for the towing light.

7. I’ve written about situational awareness previously in this column, but it’s important to bring it up again in this context. Situational awareness is consciously making yourself sensitive to what’s happening on your boat and, especially with regard to ships, around it. If you’re aware, you can prepare. Know what’s going on around you and anticipate what is ahead. It will save you from making last-minute decisions to (hopefully) keep you out of danger.